Server Rack

1. A server rack for mounting a server unit, comprising: a rack frame comprising a first support post, a second support post, a third support post, and a fourth support post cooperatively bounding a rectangular space for accommodating the server unit, wherein the first and second support posts are arranged in front of the third and fourth support posts, and respectively array with the third and forth support posts and along a lengthwise direction of the rack frame, the first and third support posts respectively array with the second and fourth support posts in a transverse direction of the rack frame, an access is defined between the first and second support posts through which the server unit slides into or out of the rack frame; two mounting brackets mounted to the rack frame selectively at a first assembly position, where one of the mounting brackets is fixed between the first and third support posts, and the other mounting bracket is fixed between the second and fourth support posts, to support the server unit, or at a second assembly position, where one of the mounting brackets is fixed between the first and second support posts to cover the access, and the other mounting bracket is fixed between the third and fourth support posts, in response to the server unit being not received in the rack frame, and four fasteners to fix the mounting brackets to the rack frame; wherein each of the fasteners comprises a screw and an abutting block defining a threaded hole; each of the first to fourth support posts comprises a side attachment flange parallel to the lengthwise direction of the rack frame, and an end attachment flange parallel to the transverse direction of the rack frame, each of the side attachment flanges and the end attachment flanges defines a positioning hole; each of the mounting brackets defines two first fixing holes respectively adjacent to opposite ends of the mounting bracket, and two second fixing holes respectively adjacent to the two first fixing holes; the first fixing holes of the mounting brackets align with the positioning holes of the corresponding side attachment flanges to enable the screws of the corresponding fasteners to extend through the first fixing holes and the corresponding positioning holes, and to be fastened in the threaded holes of the abutting blocks, in response to the mounting brackets being at the first position; and the second fixing holes of the mounting brackets align with the positioning holes of the corresponding end attachment flanges to enable the screws of the corresponding fasteners to extend through the second fixing holes and the corresponding positioning holes, and to be fastened in the threaded holes of the abutting blocks, in response to the mounting brackets being at the second position wherein the first fixing holes of each of the mounting brackets are arranged between the second fixing holes of the mounting brackets; wherein each of the mounting brackets includes a rectangular base plate, and two side plates respectively perpendicularly extending from opposite sides of the base plate, the first fixing holes and the second fixing holes are defined in the base plate.